If you send through a MUA (like Thunderbird) that uses Gmail's SMTP then Gmail do expose your IP address. Most other email providers do the same. > Under norma

If you send through a MUA (like Thunderbird) that uses Gmail's SMTP then Gmail do expose your IP address. Most other email providers do the same. > Under normal circumstances your email client (MUA) connects to your email service provider (MTA), which then sends the email to the MTA of the recipient. So the IP of your MTA (email hosting service), not your MUA (your computer) is exposed. This is incorrect, most email providers' MTA includes the MUA's IP address in the headers.